In recent years, wireless communications devices mounting Bluetooth have been widely spreading. As such wireless communications devices mounting Bluetooth, there are the above-explained mobile phones and other mobile terminals and also dial-up routers and other wireless gateways.
Such Bluetooth mounting mobile terminals and wireless gateways generally often employ the “low-consumption mode” defined in the Bluetooth specifications. This low-consumption mode is generally applied when there is no longer any data to be transferred between (i) an above Bluetooth mounting mobile terminal or other wireless communications device and (ii) an opposing Bluetooth mounting device engaged, in close distance wireless communications by Bluetooth, with this (i). This is to reduce the power consumption of the battery built-in the wireless communications device and opposing device.
As an example of known art designed to reduce the battery power consumption, there is the following Patent Document 1 (wireless type transmitter/receiver set). Further, as an example of known art designed to reduce the battery power consumption in a Bluetooth mounting wireless communications device employing the low-consumption mode, there is the following Patent Document 2 (mobile station equipped with close distance wireless function and method of reduction of its power consumption).
The Bluetooth mounting wireless communications device according to the latter Patent Document 2 is partially common with the Bluetooth mounting wireless communications device according to the present invention in the point that their objects are lowering the power consumption, but the two differ in the means for achieving the object. The means according to Patent Document 2 is to prevent useless electric waves from being emitted. On the other hand, the means of the present invention, as explained in detail later, is to provide the optimum low-consumption mode in accordance with the characteristics of the provided service and does not remain only the means of preventing useless electric waves from being emitted. Accordingly, as explained later, there may be the situation where the low-consumption mode must not be shifted to may occur depending on the characteristics of the provided service.
[Patent Document 1] Japanese Patent Publication (A) No. 2002-84361
[Patent Document 2] Japanese Patent Publication (A) No. 2003-37545